Teen Driving and Motor Vehicle Crashes

Crash Statistics 2006 – Over 43,000 Killed In Crashes Nationwide 2006 – Over 43,000 Killed In Crashes Nationwide 2006 – Over 770 Killed In Crashes In NJ 2006 – Over 770 Killed In Crashes In NJ 2006 – Over 300,000 Crashes Reported In NJ 2006 – Over 300,000 Crashes Reported In NJ

Cause of Death Age NHTSA 2003 #1 - MV Traffic Crashes (5,988) #1 - MV Traffic Crashes (5,988) #2 – Homicide (2,489) #2 – Homicide (2,489) #3 – Suicide (1,813) #3 – Suicide (1,813) #4 - Accidental Poisoning (752) #4 - Accidental Poisoning (752) #5 – Cancer (749) #5 – Cancer (749)

Cause of Death Age NHTSA 2003

MV Crashes #1 Cause of Death for Youths Approx 1/3 Of All Deaths In This Age Group. Approx 1/3 Of All Deaths In This Age Group. More Than #2 - #5 Combined More Than #2 - #5 Combined Why? Why? –Inexperience –Easily Distracted Driver Inattention #1 Cause Of Fatal Collisions In NJ Driver Inattention #1 Cause Of Fatal Collisions In NJ

What Can We Do?

The Three Es Engineering Engineering Enforcement Enforcement Education Education

Avoiding Crashes We Must Know Our Limitations We Must Know Our Limitations Human Limitations Human Limitations Vehicle Limitations Vehicle Limitations

Human Limitations Physical Limitations Physical Limitations Mental Limitations Mental Limitations

Three Collisions Human Limitations Vehicle Collision Vehicle Collision –Initial Crash Human Collision Human Collision –Body Into Interior Of Vehicle Internal Collision Internal Collision –Internal Injuries/Lacerations –Transection of Aorta –Brain Injuries

Cranial Cavity

Three Collisions

Three Collisions Human Limitations Speed Kills? Speed Kills? –Sudden Stop –Tremendous Forces Multiply Weight By Speed Multiply Weight By Speed –Delta V (Velocity Change) –Occupant Restraints Increase Time During Delta V

Reducing Forces of the Human Collision Occupant Restraints Occupant Restraints Seat Belts Seat Belts Air Bags Air Bags

Occupant Restraints Reducing The Effect Of The Human Collision Decrease Injury By Increasing Delta V Time Decrease Injury By Increasing Delta V Time Hold Occupants In Place During Collision Hold Occupants In Place During Collision Unrestrained Occupants Act As Human Bullets Unrestrained Occupants Act As Human Bullets

Occupant Restraints Reducing The Effect Of The Human Collision Lap Belt Lap Belt –Hold Occupant In Position Shoulder Harness Shoulder Harness –Stops Jack Knife Effect Air Bag Air Bag –Prevents Head Strikes

Perception And Reaction Human Limitations What Is It? What Is It? –Time Needed To Perceive And React –No Instant Reactions How Long? How Long? –1.5 Seconds Average Daytime Daytime Experienced Drivers Experienced Drivers

Visual Acuity Human Limitations Eye Function Eye Function –Rods Vs Cones Rods Rods –Are More Sensitive –Not Sensitive To Color Cones Cones –Sensitive to Color –Fovea Centralis (All Cones)

Visual Acuity Human Limitations

Conspicuity At Night Reduced Lighting Reduced Lighting –Shades Of Grey –Over Driving Headlights –Pedestrian Visibility

Vehicle Limitations Traction Traction Braking Braking Lateral Acceleration (Cornering) Lateral Acceleration (Cornering)

Vehicle Handling Friction And Handling Friction And Handling –Friction Circle Straight Roads Straight Roads Curves Curves –Inertial Forces –Critical Curve Speed

Friction Circle

Limitations Human Human Vehicle (Mechanical) Vehicle (Mechanical) Driving Is A Learned Behavior Driving Is A Learned Behavior New Drivers Need More Time To React New Drivers Need More Time To React More Time More Time –Increased Following Distances –Reduced Speeds

Perception And Reaction Human Limitations What Is It? What Is It? –Time Needed To Perceive And React –No Instant Reactions How Long? How Long? –1.5 Seconds Average Daytime Daytime Experienced Drivers Experienced Drivers

Perception And Reaction More Time Needed For: More Time Needed For: –Night –Inexperienced Drivers –Adverse Weather Following Distance Following Distance –2 Seconds –More For New Drivers

Speed Issues Speed Is A Contributing Factor In Most Serious And Fatal Crashes Speed Is A Contributing Factor In Most Serious And Fatal Crashes Speed Increases Stopping Distance Speed Increases Stopping Distance –Perception/Reaction –Braking Speed Decreases Percep/React Time Speed Decreases Percep/React Time Speed + Reduced Visibility = Bad Speed + Reduced Visibility = Bad –Night, Rain, Snow, Fog

Speed Issues How Fast Are We Really Going How Fast Are We Really Going MPH or FPS MPH or FPS MPH * = FPS MPH * = FPS

Speed Issues MPH vs. FPS MPH vs. FPS 25mph = 36.65fps 25mph = 36.65fps 35mph = 51.31fps 35mph = 51.31fps 45mph = 65.97fps 45mph = 65.97fps 55mph = 80.63fps 55mph = 80.63fps 65mph = 95.29fps 65mph = 95.29fps 75mph = fps 75mph = fps

Speed Issues Perception/Reaction Distance Perception/Reaction Distance Speed * * 1.5 sec Speed * * 1.5 sec 25mph – 54.9 Feet 25mph – 54.9 Feet 35mph – 76.9 Feet 35mph – 76.9 Feet 45mph – 98.9 Feet 45mph – 98.9 Feet 55mph – Feet 55mph – Feet 65mph – Feet 65mph – Feet 75mph – Feet 75mph – Feet

Speed Issues Braking Distance Braking Distance Dependent on Speed and Surface Friction Dependent on Speed and Surface Friction Lower Friction Increases Braking Distance Lower Friction Increases Braking Distance Dry Roads Have Highest Friction Dry Roads Have Highest Friction

Speed Issues Roadway Friction Values (Approx) Roadway Friction Values (Approx) Dry Pavement f=0.6 to 0.8 Dry Pavement f=0.6 to 0.8 Wet Pavement f=0.45 to 0.65 Wet Pavement f=0.45 to 0.65 Snow Covered f=0.3 to 0.55 Snow Covered f=0.3 to 0.55 Ice Covered f=0.05 to 0.2 Ice Covered f=0.05 to 0.2

Speed Issues Braking Distance Formula Braking Distance Formula

Speed Issues Dry Pavement Braking (f=0.7) Dry Pavement Braking (f=0.7) 25mph – 29.7 Feet 25mph – 29.7 Feet 35mph – 58.3 Feet 35mph – 58.3 Feet 45mph – 96.4 Feet 45mph – 96.4 Feet 55mph – 144 Feet 55mph – 144 Feet 65mph – Feet 65mph – Feet 75mph – Feet 75mph – Feet

Speed Issues Dry Pavement Braking (f=0.7)

Speed Issues Slide to Stop Slide to Stop Different Surfaces at 45mph Different Surfaces at 45mph Dry Feet (f=0.7) Dry Feet (f=0.7) Wet – Feet (f=0.55) Wet – Feet (f=0.55) Snow – Feet (f=0.4) Snow – Feet (f=0.4) Ice – Feet (f=0.2) Ice – Feet (f=0.2)

Total Stopping Distance Combine Combine –Perception/Reaction Distance –Braking Distance

Stopping Distance Dry Pavement Percep/React + Braking=Total Stop D Percep/React + Braking=Total Stop D 25mph – 84.6 Feet 25mph – 84.6 Feet 35mph – Feet 35mph – Feet 45mph Feet 45mph Feet 55mph – Feet 55mph – Feet 65mph – 344 Feet 65mph – 344 Feet 75mph – Feet 75mph – Feet

Big Brother Is Watching Crash Reconstruction Crash Reconstruction Calculating Speed From: Calculating Speed From: –Tire Marks –Crush Damage –Momentum Analysis –Computer Modeling Air Bag Module Air Bag Module Car Chip Car Chip

Legal Consequences Tickets Tickets Suspension Suspension Increased Insurance Costs Increased Insurance Costs Criminal Consequences Criminal Consequences –Accident While Suspended –Vehicular Assault –Vehicular Homicide